Intrusion Prevention Systems (IPS) are used to protect computer networks against malicious incoming traffic. However, the effectiveness of an IPS is limited due to the fact that an IPS only blocks traffic for which it has a “signature.” A signature being a specific rule for content filtering to detect electronic threats. Accordingly, an IPS may not block an exploit for a vulnerability the vendor is not aware of, or for which there is no patch available. A zero-day exploit is one that takes advantage of a security vulnerability on the same day that the vulnerability becomes generally known, or before a signature has been developed and the exploit is in circulation (in the wild).
Zero-day protection is the ability to provide protection against zero-day exploits. Because zero-day attacks are generally unknown to the public, it is often difficult to defend against them. Zero-day attacks are often effective against “secure” networks and can remain undetected even after they are launched.
Techniques exist to limit the effectiveness of zero-day memory corruption-type vulnerabilities, such as buffer overflows. These protection mechanisms exist in contemporary operating systems such as SUN MICROSYSTEMS SOLARIS, LINUX, UNIX, and UNIX-like environments. Versions of MICROSOFT WINDOWS XP Service Pack 2 and later include limited protection against generic memory corruption-type vulnerabilities. Desktop and server protection software also exists to mitigate zero-day buffer overflow vulnerabilities. Typically, these technologies involve heuristic determination analysis, stopping the attacks before they cause any harm. However, this type of analysis is prone to a high incidence of false positive results.